Disclosed is a battery having an improved life. Specifically disclosed is a battery which comprises an electric power generating element in which one or more unit cell layers are stacked, each being constituted by sequentially laminating or stacking a positive electrode, an electrolyte and a negative electrode; a first collector plate which is provided on the outermost positive electrode surface of the electric power generating element; a second collector plate which is provided on the outermost negative electrode surface of the electric power generating element; a convex or protruding portion provided on the first collector plate and/or the second collector plate with a width that is not less than a half of the width of the end edge of the collector plate; and a terminal which is attached to the convex portion for retrieving electric current from the convex portion.